Have you seen the parking lot at the gym this time of year? It’s packed! That’s because most people list living a healthier lifestyle as one of their New Year’s resolutions. Heart disease is the number one cause of death in the United States for both men and women. CDC statistics show that approximately 610,000 people in the U.S. die of heart disease every year. This is the equivalent of one out of every four deaths. Despite these grim statistics, there is some good news. Even people in middle age—who have been living a sedentary life for decades—can reverse their risk of heart failure by kick-starting a fitness regime. According to the Institute for Exercise and Environmental Medicine researchers, men and women who began a robust fitness routine in middle age were able to reverse the damage of a sedentary lifestyle by improving the elasticity of their hearts. This prevented the risk of future heart failure.

The body’s own immune system could thwart some efforts to develop gene therapies based on the trendy genome-editing tool called CRISPR-Cas9. About 79 percent of 34 blood donors tested had antibodies against the Cas9 protein from Staphylococcus aureus bacteria, Stanford University researchers report January 5 at bioRxiv.org. About 65 percent of donors had antibodies against the Cas9 protein from Streptococcus pyogenes. The immune reactions may be a technical glitch that researchers will need to work around, but probably aren’t a safety concern as long as cells are edited in lab dishes rather than in the body.

Researchers at the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA have, for the first time, coaxed human stem cells to become sensory interneurons — the cells that give us our sense of touch. The new protocol could be a step toward stem cell–based therapies to restore sensation in paralyzed people who have lost feeling in parts of their body. Sensory interneurons, a class of neurons in the spinal cord, are responsible for relaying information from throughout the body to the central nervous system, which enables the sense of touch. The lack of a sense of touch greatly affects people who are paralyzed. For example, they often cannot feel the touch of another person, and the inability to feel pain leaves them susceptible to burns from inadvertent contact with a hot surface.